1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 /* Copyright (C) 2019 Facebook */ 3 4 #ifndef _GNU_SOURCE 5 #define _GNU_SOURCE 6 #endif 7 #include <ctype.h> 8 #include <errno.h> 9 #include <fcntl.h> 10 #include <linux/err.h> 11 #include <stdbool.h> 12 #include <stdio.h> 13 #include <string.h> 14 #include <unistd.h> 15 #include <bpf/bpf.h> 16 #include <bpf/libbpf.h> 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 #include <sys/mman.h> 20 #include <bpf/btf.h> 21 22 #include "json_writer.h" 23 #include "main.h" 24 25 #define MAX_OBJ_NAME_LEN 64 26 27 static void sanitize_identifier(char *name) 28 { 29 int i; 30 31 for (i = 0; name[i]; i++) 32 if (!isalnum(name[i]) && name[i] != '_') 33 name[i] = '_'; 34 } 35 36 static bool str_has_prefix(const char *str, const char *prefix) 37 { 38 return strncmp(str, prefix, strlen(prefix)) == 0; 39 } 40 41 static bool str_has_suffix(const char *str, const char *suffix) 42 { 43 size_t i, n1 = strlen(str), n2 = strlen(suffix); 44 45 if (n1 < n2) 46 return false; 47 48 for (i = 0; i < n2; i++) { 49 if (str[n1 - i - 1] != suffix[n2 - i - 1]) 50 return false; 51 } 52 53 return true; 54 } 55 56 static void get_obj_name(char *name, const char *file) 57 { 58 /* Using basename() GNU version which doesn't modify arg. */ 59 strncpy(name, basename(file), MAX_OBJ_NAME_LEN - 1); 60 name[MAX_OBJ_NAME_LEN - 1] = '\0'; 61 if (str_has_suffix(name, ".o")) 62 name[strlen(name) - 2] = '\0'; 63 sanitize_identifier(name); 64 } 65 66 static void get_header_guard(char *guard, const char *obj_name) 67 { 68 int i; 69 70 sprintf(guard, "__%s_SKEL_H__", obj_name); 71 for (i = 0; guard[i]; i++) 72 guard[i] = toupper(guard[i]); 73 } 74 75 static bool get_map_ident(const struct bpf_map *map, char *buf, size_t buf_sz) 76 { 77 static const char *sfxs[] = { ".data", ".rodata", ".bss", ".kconfig" }; 78 const char *name = bpf_map__name(map); 79 int i, n; 80 81 if (!bpf_map__is_internal(map)) { 82 snprintf(buf, buf_sz, "%s", name); 83 return true; 84 } 85 86 for (i = 0, n = ARRAY_SIZE(sfxs); i < n; i++) { 87 const char *sfx = sfxs[i], *p; 88 89 p = strstr(name, sfx); 90 if (p) { 91 snprintf(buf, buf_sz, "%s", p + 1); 92 sanitize_identifier(buf); 93 return true; 94 } 95 } 96 97 return false; 98 } 99 100 static bool get_datasec_ident(const char *sec_name, char *buf, size_t buf_sz) 101 { 102 static const char *pfxs[] = { ".data", ".rodata", ".bss", ".kconfig" }; 103 int i, n; 104 105 for (i = 0, n = ARRAY_SIZE(pfxs); i < n; i++) { 106 const char *pfx = pfxs[i]; 107 108 if (str_has_prefix(sec_name, pfx)) { 109 snprintf(buf, buf_sz, "%s", sec_name + 1); 110 sanitize_identifier(buf); 111 return true; 112 } 113 } 114 115 return false; 116 } 117 118 static void codegen_btf_dump_printf(void *ctx, const char *fmt, va_list args) 119 { 120 vprintf(fmt, args); 121 } 122 123 static int codegen_datasec_def(struct bpf_object *obj, 124 struct btf *btf, 125 struct btf_dump *d, 126 const struct btf_type *sec, 127 const char *obj_name) 128 { 129 const char *sec_name = btf__name_by_offset(btf, sec->name_off); 130 const struct btf_var_secinfo *sec_var = btf_var_secinfos(sec); 131 int i, err, off = 0, pad_cnt = 0, vlen = btf_vlen(sec); 132 char var_ident[256], sec_ident[256]; 133 bool strip_mods = false; 134 135 if (!get_datasec_ident(sec_name, sec_ident, sizeof(sec_ident))) 136 return 0; 137 138 if (strcmp(sec_name, ".kconfig") != 0) 139 strip_mods = true; 140 141 printf(" struct %s__%s {\n", obj_name, sec_ident); 142 for (i = 0; i < vlen; i++, sec_var++) { 143 const struct btf_type *var = btf__type_by_id(btf, sec_var->type); 144 const char *var_name = btf__name_by_offset(btf, var->name_off); 145 DECLARE_LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts, 146 .field_name = var_ident, 147 .indent_level = 2, 148 .strip_mods = strip_mods, 149 ); 150 int need_off = sec_var->offset, align_off, align; 151 __u32 var_type_id = var->type; 152 153 /* static variables are not exposed through BPF skeleton */ 154 if (btf_var(var)->linkage == BTF_VAR_STATIC) 155 continue; 156 157 if (off > need_off) { 158 p_err("Something is wrong for %s's variable #%d: need offset %d, already at %d.\n", 159 sec_name, i, need_off, off); 160 return -EINVAL; 161 } 162 163 align = btf__align_of(btf, var->type); 164 if (align <= 0) { 165 p_err("Failed to determine alignment of variable '%s': %d", 166 var_name, align); 167 return -EINVAL; 168 } 169 /* Assume 32-bit architectures when generating data section 170 * struct memory layout. Given bpftool can't know which target 171 * host architecture it's emitting skeleton for, we need to be 172 * conservative and assume 32-bit one to ensure enough padding 173 * bytes are generated for pointer and long types. This will 174 * still work correctly for 64-bit architectures, because in 175 * the worst case we'll generate unnecessary padding field, 176 * which on 64-bit architectures is not strictly necessary and 177 * would be handled by natural 8-byte alignment. But it still 178 * will be a correct memory layout, based on recorded offsets 179 * in BTF. 180 */ 181 if (align > 4) 182 align = 4; 183 184 align_off = (off + align - 1) / align * align; 185 if (align_off != need_off) { 186 printf("\t\tchar __pad%d[%d];\n", 187 pad_cnt, need_off - off); 188 pad_cnt++; 189 } 190 191 /* sanitize variable name, e.g., for static vars inside 192 * a function, it's name is '<function name>.<variable name>', 193 * which we'll turn into a '<function name>_<variable name>' 194 */ 195 var_ident[0] = '\0'; 196 strncat(var_ident, var_name, sizeof(var_ident) - 1); 197 sanitize_identifier(var_ident); 198 199 printf("\t\t"); 200 err = btf_dump__emit_type_decl(d, var_type_id, &opts); 201 if (err) 202 return err; 203 printf(";\n"); 204 205 off = sec_var->offset + sec_var->size; 206 } 207 printf(" } *%s;\n", sec_ident); 208 return 0; 209 } 210 211 static int codegen_datasecs(struct bpf_object *obj, const char *obj_name) 212 { 213 struct btf *btf = bpf_object__btf(obj); 214 int n = btf__type_cnt(btf); 215 struct btf_dump *d; 216 struct bpf_map *map; 217 const struct btf_type *sec; 218 char sec_ident[256], map_ident[256]; 219 int i, err = 0; 220 221 d = btf_dump__new(btf, codegen_btf_dump_printf, NULL, NULL); 222 err = libbpf_get_error(d); 223 if (err) 224 return err; 225 226 bpf_object__for_each_map(map, obj) { 227 /* only generate definitions for memory-mapped internal maps */ 228 if (!bpf_map__is_internal(map)) 229 continue; 230 if (!(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) 231 continue; 232 233 if (!get_map_ident(map, map_ident, sizeof(map_ident))) 234 continue; 235 236 sec = NULL; 237 for (i = 1; i < n; i++) { 238 const struct btf_type *t = btf__type_by_id(btf, i); 239 const char *name; 240 241 if (!btf_is_datasec(t)) 242 continue; 243 244 name = btf__str_by_offset(btf, t->name_off); 245 if (!get_datasec_ident(name, sec_ident, sizeof(sec_ident))) 246 continue; 247 248 if (strcmp(sec_ident, map_ident) == 0) { 249 sec = t; 250 break; 251 } 252 } 253 254 /* In some cases (e.g., sections like .rodata.cst16 containing 255 * compiler allocated string constants only) there will be 256 * special internal maps with no corresponding DATASEC BTF 257 * type. In such case, generate empty structs for each such 258 * map. It will still be memory-mapped and its contents 259 * accessible from user-space through BPF skeleton. 260 */ 261 if (!sec) { 262 printf(" struct %s__%s {\n", obj_name, map_ident); 263 printf(" } *%s;\n", map_ident); 264 } else { 265 err = codegen_datasec_def(obj, btf, d, sec, obj_name); 266 if (err) 267 goto out; 268 } 269 } 270 271 272 out: 273 btf_dump__free(d); 274 return err; 275 } 276 277 static void codegen(const char *template, ...) 278 { 279 const char *src, *end; 280 int skip_tabs = 0, n; 281 char *s, *dst; 282 va_list args; 283 char c; 284 285 n = strlen(template); 286 s = malloc(n + 1); 287 if (!s) 288 exit(-1); 289 src = template; 290 dst = s; 291 292 /* find out "baseline" indentation to skip */ 293 while ((c = *src++)) { 294 if (c == '\t') { 295 skip_tabs++; 296 } else if (c == '\n') { 297 break; 298 } else { 299 p_err("unrecognized character at pos %td in template '%s': '%c'", 300 src - template - 1, template, c); 301 free(s); 302 exit(-1); 303 } 304 } 305 306 while (*src) { 307 /* skip baseline indentation tabs */ 308 for (n = skip_tabs; n > 0; n--, src++) { 309 if (*src != '\t') { 310 p_err("not enough tabs at pos %td in template '%s'", 311 src - template - 1, template); 312 free(s); 313 exit(-1); 314 } 315 } 316 /* trim trailing whitespace */ 317 end = strchrnul(src, '\n'); 318 for (n = end - src; n > 0 && isspace(src[n - 1]); n--) 319 ; 320 memcpy(dst, src, n); 321 dst += n; 322 if (*end) 323 *dst++ = '\n'; 324 src = *end ? end + 1 : end; 325 } 326 *dst++ = '\0'; 327 328 /* print out using adjusted template */ 329 va_start(args, template); 330 n = vprintf(s, args); 331 va_end(args); 332 333 free(s); 334 } 335 336 static void print_hex(const char *data, int data_sz) 337 { 338 int i, len; 339 340 for (i = 0, len = 0; i < data_sz; i++) { 341 int w = data[i] ? 4 : 2; 342 343 len += w; 344 if (len > 78) { 345 printf("\\\n"); 346 len = w; 347 } 348 if (!data[i]) 349 printf("\\0"); 350 else 351 printf("\\x%02x", (unsigned char)data[i]); 352 } 353 } 354 355 static size_t bpf_map_mmap_sz(const struct bpf_map *map) 356 { 357 long page_sz = sysconf(_SC_PAGE_SIZE); 358 size_t map_sz; 359 360 map_sz = (size_t)roundup(bpf_map__value_size(map), 8) * bpf_map__max_entries(map); 361 map_sz = roundup(map_sz, page_sz); 362 return map_sz; 363 } 364 365 static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name) 366 { 367 struct bpf_program *prog; 368 369 bpf_object__for_each_program(prog, obj) { 370 const char *tp_name; 371 372 codegen("\ 373 \n\ 374 \n\ 375 static inline int \n\ 376 %1$s__%2$s__attach(struct %1$s *skel) \n\ 377 { \n\ 378 int prog_fd = skel->progs.%2$s.prog_fd; \n\ 379 ", obj_name, bpf_program__name(prog)); 380 381 switch (bpf_program__get_type(prog)) { 382 case BPF_PROG_TYPE_RAW_TRACEPOINT: 383 tp_name = strchr(bpf_program__section_name(prog), '/') + 1; 384 printf("\tint fd = bpf_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name); 385 break; 386 case BPF_PROG_TYPE_TRACING: 387 printf("\tint fd = bpf_raw_tracepoint_open(NULL, prog_fd);\n"); 388 break; 389 default: 390 printf("\tint fd = ((void)prog_fd, 0); /* auto-attach not supported */\n"); 391 break; 392 } 393 codegen("\ 394 \n\ 395 \n\ 396 if (fd > 0) \n\ 397 skel->links.%1$s_fd = fd; \n\ 398 return fd; \n\ 399 } \n\ 400 ", bpf_program__name(prog)); 401 } 402 403 codegen("\ 404 \n\ 405 \n\ 406 static inline int \n\ 407 %1$s__attach(struct %1$s *skel) \n\ 408 { \n\ 409 int ret = 0; \n\ 410 \n\ 411 ", obj_name); 412 413 bpf_object__for_each_program(prog, obj) { 414 codegen("\ 415 \n\ 416 ret = ret < 0 ? ret : %1$s__%2$s__attach(skel); \n\ 417 ", obj_name, bpf_program__name(prog)); 418 } 419 420 codegen("\ 421 \n\ 422 return ret < 0 ? ret : 0; \n\ 423 } \n\ 424 \n\ 425 static inline void \n\ 426 %1$s__detach(struct %1$s *skel) \n\ 427 { \n\ 428 ", obj_name); 429 430 bpf_object__for_each_program(prog, obj) { 431 codegen("\ 432 \n\ 433 skel_closenz(skel->links.%1$s_fd); \n\ 434 ", bpf_program__name(prog)); 435 } 436 437 codegen("\ 438 \n\ 439 } \n\ 440 "); 441 } 442 443 static void codegen_destroy(struct bpf_object *obj, const char *obj_name) 444 { 445 struct bpf_program *prog; 446 struct bpf_map *map; 447 char ident[256]; 448 449 codegen("\ 450 \n\ 451 static void \n\ 452 %1$s__destroy(struct %1$s *skel) \n\ 453 { \n\ 454 if (!skel) \n\ 455 return; \n\ 456 %1$s__detach(skel); \n\ 457 ", 458 obj_name); 459 460 bpf_object__for_each_program(prog, obj) { 461 codegen("\ 462 \n\ 463 skel_closenz(skel->progs.%1$s.prog_fd); \n\ 464 ", bpf_program__name(prog)); 465 } 466 467 bpf_object__for_each_map(map, obj) { 468 if (!get_map_ident(map, ident, sizeof(ident))) 469 continue; 470 if (bpf_map__is_internal(map) && 471 (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) 472 printf("\tmunmap(skel->%1$s, %2$zd);\n", 473 ident, bpf_map_mmap_sz(map)); 474 codegen("\ 475 \n\ 476 skel_closenz(skel->maps.%1$s.map_fd); \n\ 477 ", ident); 478 } 479 codegen("\ 480 \n\ 481 free(skel); \n\ 482 } \n\ 483 ", 484 obj_name); 485 } 486 487 static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *header_guard) 488 { 489 DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); 490 struct bpf_map *map; 491 char ident[256]; 492 int err = 0; 493 494 err = bpf_object__gen_loader(obj, &opts); 495 if (err) 496 return err; 497 498 err = bpf_object__load(obj); 499 if (err) { 500 p_err("failed to load object file"); 501 goto out; 502 } 503 /* If there was no error during load then gen_loader_opts 504 * are populated with the loader program. 505 */ 506 507 /* finish generating 'struct skel' */ 508 codegen("\ 509 \n\ 510 }; \n\ 511 ", obj_name); 512 513 514 codegen_attach_detach(obj, obj_name); 515 516 codegen_destroy(obj, obj_name); 517 518 codegen("\ 519 \n\ 520 static inline struct %1$s * \n\ 521 %1$s__open(void) \n\ 522 { \n\ 523 struct %1$s *skel; \n\ 524 \n\ 525 skel = calloc(sizeof(*skel), 1); \n\ 526 if (!skel) \n\ 527 goto cleanup; \n\ 528 skel->ctx.sz = (void *)&skel->links - (void *)skel; \n\ 529 ", 530 obj_name, opts.data_sz); 531 bpf_object__for_each_map(map, obj) { 532 const void *mmap_data = NULL; 533 size_t mmap_size = 0; 534 535 if (!get_map_ident(map, ident, sizeof(ident))) 536 continue; 537 538 if (!bpf_map__is_internal(map) || 539 !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) 540 continue; 541 542 codegen("\ 543 \n\ 544 skel->%1$s = \n\ 545 mmap(NULL, %2$zd, PROT_READ | PROT_WRITE,\n\ 546 MAP_SHARED | MAP_ANONYMOUS, -1, 0); \n\ 547 if (skel->%1$s == (void *) -1) \n\ 548 goto cleanup; \n\ 549 memcpy(skel->%1$s, (void *)\"\\ \n\ 550 ", ident, bpf_map_mmap_sz(map)); 551 mmap_data = bpf_map__initial_value(map, &mmap_size); 552 print_hex(mmap_data, mmap_size); 553 printf("\", %2$zd);\n" 554 "\tskel->maps.%1$s.initial_value = (__u64)(long)skel->%1$s;\n", 555 ident, mmap_size); 556 } 557 codegen("\ 558 \n\ 559 return skel; \n\ 560 cleanup: \n\ 561 %1$s__destroy(skel); \n\ 562 return NULL; \n\ 563 } \n\ 564 \n\ 565 static inline int \n\ 566 %1$s__load(struct %1$s *skel) \n\ 567 { \n\ 568 struct bpf_load_and_run_opts opts = {}; \n\ 569 int err; \n\ 570 \n\ 571 opts.ctx = (struct bpf_loader_ctx *)skel; \n\ 572 opts.data_sz = %2$d; \n\ 573 opts.data = (void *)\"\\ \n\ 574 ", 575 obj_name, opts.data_sz); 576 print_hex(opts.data, opts.data_sz); 577 codegen("\ 578 \n\ 579 \"; \n\ 580 "); 581 582 codegen("\ 583 \n\ 584 opts.insns_sz = %d; \n\ 585 opts.insns = (void *)\"\\ \n\ 586 ", 587 opts.insns_sz); 588 print_hex(opts.insns, opts.insns_sz); 589 codegen("\ 590 \n\ 591 \"; \n\ 592 err = bpf_load_and_run(&opts); \n\ 593 if (err < 0) \n\ 594 return err; \n\ 595 ", obj_name); 596 bpf_object__for_each_map(map, obj) { 597 const char *mmap_flags; 598 599 if (!get_map_ident(map, ident, sizeof(ident))) 600 continue; 601 602 if (!bpf_map__is_internal(map) || 603 !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) 604 continue; 605 606 if (bpf_map__def(map)->map_flags & BPF_F_RDONLY_PROG) 607 mmap_flags = "PROT_READ"; 608 else 609 mmap_flags = "PROT_READ | PROT_WRITE"; 610 611 printf("\tskel->%1$s =\n" 612 "\t\tmmap(skel->%1$s, %2$zd, %3$s, MAP_SHARED | MAP_FIXED,\n" 613 "\t\t\tskel->maps.%1$s.map_fd, 0);\n", 614 ident, bpf_map_mmap_sz(map), mmap_flags); 615 } 616 codegen("\ 617 \n\ 618 return 0; \n\ 619 } \n\ 620 \n\ 621 static inline struct %1$s * \n\ 622 %1$s__open_and_load(void) \n\ 623 { \n\ 624 struct %1$s *skel; \n\ 625 \n\ 626 skel = %1$s__open(); \n\ 627 if (!skel) \n\ 628 return NULL; \n\ 629 if (%1$s__load(skel)) { \n\ 630 %1$s__destroy(skel); \n\ 631 return NULL; \n\ 632 } \n\ 633 return skel; \n\ 634 } \n\ 635 ", obj_name); 636 637 codegen("\ 638 \n\ 639 \n\ 640 #endif /* %s */ \n\ 641 ", 642 header_guard); 643 err = 0; 644 out: 645 return err; 646 } 647 648 static int do_skeleton(int argc, char **argv) 649 { 650 char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; 651 size_t i, map_cnt = 0, prog_cnt = 0, file_sz, mmap_sz; 652 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); 653 char obj_name[MAX_OBJ_NAME_LEN] = "", *obj_data; 654 struct bpf_object *obj = NULL; 655 const char *file; 656 char ident[256]; 657 struct bpf_program *prog; 658 int fd, err = -1; 659 struct bpf_map *map; 660 struct btf *btf; 661 struct stat st; 662 663 if (!REQ_ARGS(1)) { 664 usage(); 665 return -1; 666 } 667 file = GET_ARG(); 668 669 while (argc) { 670 if (!REQ_ARGS(2)) 671 return -1; 672 673 if (is_prefix(*argv, "name")) { 674 NEXT_ARG(); 675 676 if (obj_name[0] != '\0') { 677 p_err("object name already specified"); 678 return -1; 679 } 680 681 strncpy(obj_name, *argv, MAX_OBJ_NAME_LEN - 1); 682 obj_name[MAX_OBJ_NAME_LEN - 1] = '\0'; 683 } else { 684 p_err("unknown arg %s", *argv); 685 return -1; 686 } 687 688 NEXT_ARG(); 689 } 690 691 if (argc) { 692 p_err("extra unknown arguments"); 693 return -1; 694 } 695 696 if (stat(file, &st)) { 697 p_err("failed to stat() %s: %s", file, strerror(errno)); 698 return -1; 699 } 700 file_sz = st.st_size; 701 mmap_sz = roundup(file_sz, sysconf(_SC_PAGE_SIZE)); 702 fd = open(file, O_RDONLY); 703 if (fd < 0) { 704 p_err("failed to open() %s: %s", file, strerror(errno)); 705 return -1; 706 } 707 obj_data = mmap(NULL, mmap_sz, PROT_READ, MAP_PRIVATE, fd, 0); 708 if (obj_data == MAP_FAILED) { 709 obj_data = NULL; 710 p_err("failed to mmap() %s: %s", file, strerror(errno)); 711 goto out; 712 } 713 if (obj_name[0] == '\0') 714 get_obj_name(obj_name, file); 715 opts.object_name = obj_name; 716 if (verifier_logs) 717 /* log_level1 + log_level2 + stats, but not stable UAPI */ 718 opts.kernel_log_level = 1 + 2 + 4; 719 obj = bpf_object__open_mem(obj_data, file_sz, &opts); 720 err = libbpf_get_error(obj); 721 if (err) { 722 char err_buf[256]; 723 724 libbpf_strerror(err, err_buf, sizeof(err_buf)); 725 p_err("failed to open BPF object file: %s", err_buf); 726 obj = NULL; 727 goto out; 728 } 729 730 bpf_object__for_each_map(map, obj) { 731 if (!get_map_ident(map, ident, sizeof(ident))) { 732 p_err("ignoring unrecognized internal map '%s'...", 733 bpf_map__name(map)); 734 continue; 735 } 736 map_cnt++; 737 } 738 bpf_object__for_each_program(prog, obj) { 739 prog_cnt++; 740 } 741 742 get_header_guard(header_guard, obj_name); 743 if (use_loader) { 744 codegen("\ 745 \n\ 746 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ 747 /* THIS FILE IS AUTOGENERATED! */ \n\ 748 #ifndef %2$s \n\ 749 #define %2$s \n\ 750 \n\ 751 #include <stdlib.h> \n\ 752 #include <bpf/bpf.h> \n\ 753 #include <bpf/skel_internal.h> \n\ 754 \n\ 755 struct %1$s { \n\ 756 struct bpf_loader_ctx ctx; \n\ 757 ", 758 obj_name, header_guard 759 ); 760 } else { 761 codegen("\ 762 \n\ 763 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ 764 \n\ 765 /* THIS FILE IS AUTOGENERATED! */ \n\ 766 #ifndef %2$s \n\ 767 #define %2$s \n\ 768 \n\ 769 #include <errno.h> \n\ 770 #include <stdlib.h> \n\ 771 #include <bpf/libbpf.h> \n\ 772 \n\ 773 struct %1$s { \n\ 774 struct bpf_object_skeleton *skeleton; \n\ 775 struct bpf_object *obj; \n\ 776 ", 777 obj_name, header_guard 778 ); 779 } 780 781 if (map_cnt) { 782 printf("\tstruct {\n"); 783 bpf_object__for_each_map(map, obj) { 784 if (!get_map_ident(map, ident, sizeof(ident))) 785 continue; 786 if (use_loader) 787 printf("\t\tstruct bpf_map_desc %s;\n", ident); 788 else 789 printf("\t\tstruct bpf_map *%s;\n", ident); 790 } 791 printf("\t} maps;\n"); 792 } 793 794 if (prog_cnt) { 795 printf("\tstruct {\n"); 796 bpf_object__for_each_program(prog, obj) { 797 if (use_loader) 798 printf("\t\tstruct bpf_prog_desc %s;\n", 799 bpf_program__name(prog)); 800 else 801 printf("\t\tstruct bpf_program *%s;\n", 802 bpf_program__name(prog)); 803 } 804 printf("\t} progs;\n"); 805 printf("\tstruct {\n"); 806 bpf_object__for_each_program(prog, obj) { 807 if (use_loader) 808 printf("\t\tint %s_fd;\n", 809 bpf_program__name(prog)); 810 else 811 printf("\t\tstruct bpf_link *%s;\n", 812 bpf_program__name(prog)); 813 } 814 printf("\t} links;\n"); 815 } 816 817 btf = bpf_object__btf(obj); 818 if (btf) { 819 err = codegen_datasecs(obj, obj_name); 820 if (err) 821 goto out; 822 } 823 if (use_loader) { 824 err = gen_trace(obj, obj_name, header_guard); 825 goto out; 826 } 827 828 codegen("\ 829 \n\ 830 }; \n\ 831 \n\ 832 static void \n\ 833 %1$s__destroy(struct %1$s *obj) \n\ 834 { \n\ 835 if (!obj) \n\ 836 return; \n\ 837 if (obj->skeleton) \n\ 838 bpf_object__destroy_skeleton(obj->skeleton);\n\ 839 free(obj); \n\ 840 } \n\ 841 \n\ 842 static inline int \n\ 843 %1$s__create_skeleton(struct %1$s *obj); \n\ 844 \n\ 845 static inline struct %1$s * \n\ 846 %1$s__open_opts(const struct bpf_object_open_opts *opts) \n\ 847 { \n\ 848 struct %1$s *obj; \n\ 849 int err; \n\ 850 \n\ 851 obj = (struct %1$s *)calloc(1, sizeof(*obj)); \n\ 852 if (!obj) { \n\ 853 errno = ENOMEM; \n\ 854 return NULL; \n\ 855 } \n\ 856 \n\ 857 err = %1$s__create_skeleton(obj); \n\ 858 if (err) \n\ 859 goto err_out; \n\ 860 \n\ 861 err = bpf_object__open_skeleton(obj->skeleton, opts);\n\ 862 if (err) \n\ 863 goto err_out; \n\ 864 \n\ 865 return obj; \n\ 866 err_out: \n\ 867 %1$s__destroy(obj); \n\ 868 errno = -err; \n\ 869 return NULL; \n\ 870 } \n\ 871 \n\ 872 static inline struct %1$s * \n\ 873 %1$s__open(void) \n\ 874 { \n\ 875 return %1$s__open_opts(NULL); \n\ 876 } \n\ 877 \n\ 878 static inline int \n\ 879 %1$s__load(struct %1$s *obj) \n\ 880 { \n\ 881 return bpf_object__load_skeleton(obj->skeleton); \n\ 882 } \n\ 883 \n\ 884 static inline struct %1$s * \n\ 885 %1$s__open_and_load(void) \n\ 886 { \n\ 887 struct %1$s *obj; \n\ 888 int err; \n\ 889 \n\ 890 obj = %1$s__open(); \n\ 891 if (!obj) \n\ 892 return NULL; \n\ 893 err = %1$s__load(obj); \n\ 894 if (err) { \n\ 895 %1$s__destroy(obj); \n\ 896 errno = -err; \n\ 897 return NULL; \n\ 898 } \n\ 899 return obj; \n\ 900 } \n\ 901 \n\ 902 static inline int \n\ 903 %1$s__attach(struct %1$s *obj) \n\ 904 { \n\ 905 return bpf_object__attach_skeleton(obj->skeleton); \n\ 906 } \n\ 907 \n\ 908 static inline void \n\ 909 %1$s__detach(struct %1$s *obj) \n\ 910 { \n\ 911 return bpf_object__detach_skeleton(obj->skeleton); \n\ 912 } \n\ 913 ", 914 obj_name 915 ); 916 917 codegen("\ 918 \n\ 919 \n\ 920 static inline const void *%1$s__elf_bytes(size_t *sz); \n\ 921 \n\ 922 static inline int \n\ 923 %1$s__create_skeleton(struct %1$s *obj) \n\ 924 { \n\ 925 struct bpf_object_skeleton *s; \n\ 926 \n\ 927 s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\ 928 if (!s) \n\ 929 goto err; \n\ 930 obj->skeleton = s; \n\ 931 \n\ 932 s->sz = sizeof(*s); \n\ 933 s->name = \"%1$s\"; \n\ 934 s->obj = &obj->obj; \n\ 935 ", 936 obj_name 937 ); 938 if (map_cnt) { 939 codegen("\ 940 \n\ 941 \n\ 942 /* maps */ \n\ 943 s->map_cnt = %zu; \n\ 944 s->map_skel_sz = sizeof(*s->maps); \n\ 945 s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\ 946 if (!s->maps) \n\ 947 goto err; \n\ 948 ", 949 map_cnt 950 ); 951 i = 0; 952 bpf_object__for_each_map(map, obj) { 953 if (!get_map_ident(map, ident, sizeof(ident))) 954 continue; 955 956 codegen("\ 957 \n\ 958 \n\ 959 s->maps[%zu].name = \"%s\"; \n\ 960 s->maps[%zu].map = &obj->maps.%s; \n\ 961 ", 962 i, bpf_map__name(map), i, ident); 963 /* memory-mapped internal maps */ 964 if (bpf_map__is_internal(map) && 965 (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) { 966 printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n", 967 i, ident); 968 } 969 i++; 970 } 971 } 972 if (prog_cnt) { 973 codegen("\ 974 \n\ 975 \n\ 976 /* programs */ \n\ 977 s->prog_cnt = %zu; \n\ 978 s->prog_skel_sz = sizeof(*s->progs); \n\ 979 s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\ 980 if (!s->progs) \n\ 981 goto err; \n\ 982 ", 983 prog_cnt 984 ); 985 i = 0; 986 bpf_object__for_each_program(prog, obj) { 987 codegen("\ 988 \n\ 989 \n\ 990 s->progs[%1$zu].name = \"%2$s\"; \n\ 991 s->progs[%1$zu].prog = &obj->progs.%2$s;\n\ 992 s->progs[%1$zu].link = &obj->links.%2$s;\n\ 993 ", 994 i, bpf_program__name(prog)); 995 i++; 996 } 997 } 998 codegen("\ 999 \n\ 1000 \n\ 1001 s->data = (void *)%2$s__elf_bytes(&s->data_sz); \n\ 1002 \n\ 1003 return 0; \n\ 1004 err: \n\ 1005 bpf_object__destroy_skeleton(s); \n\ 1006 return -ENOMEM; \n\ 1007 } \n\ 1008 \n\ 1009 static inline const void *%2$s__elf_bytes(size_t *sz) \n\ 1010 { \n\ 1011 *sz = %1$d; \n\ 1012 return (const void *)\"\\ \n\ 1013 " 1014 , file_sz, obj_name); 1015 1016 /* embed contents of BPF object file */ 1017 print_hex(obj_data, file_sz); 1018 1019 codegen("\ 1020 \n\ 1021 \"; \n\ 1022 } \n\ 1023 \n\ 1024 #endif /* %s */ \n\ 1025 ", 1026 header_guard); 1027 err = 0; 1028 out: 1029 bpf_object__close(obj); 1030 if (obj_data) 1031 munmap(obj_data, mmap_sz); 1032 close(fd); 1033 return err; 1034 } 1035 1036 static int do_object(int argc, char **argv) 1037 { 1038 struct bpf_linker *linker; 1039 const char *output_file, *file; 1040 int err = 0; 1041 1042 if (!REQ_ARGS(2)) { 1043 usage(); 1044 return -1; 1045 } 1046 1047 output_file = GET_ARG(); 1048 1049 linker = bpf_linker__new(output_file, NULL); 1050 if (!linker) { 1051 p_err("failed to create BPF linker instance"); 1052 return -1; 1053 } 1054 1055 while (argc) { 1056 file = GET_ARG(); 1057 1058 err = bpf_linker__add_file(linker, file, NULL); 1059 if (err) { 1060 p_err("failed to link '%s': %s (%d)", file, strerror(err), err); 1061 goto out; 1062 } 1063 } 1064 1065 err = bpf_linker__finalize(linker); 1066 if (err) { 1067 p_err("failed to finalize ELF file: %s (%d)", strerror(err), err); 1068 goto out; 1069 } 1070 1071 err = 0; 1072 out: 1073 bpf_linker__free(linker); 1074 return err; 1075 } 1076 1077 static int do_help(int argc, char **argv) 1078 { 1079 if (json_output) { 1080 jsonw_null(json_wtr); 1081 return 0; 1082 } 1083 1084 fprintf(stderr, 1085 "Usage: %1$s %2$s object OUTPUT_FILE INPUT_FILE [INPUT_FILE...]\n" 1086 " %1$s %2$s skeleton FILE [name OBJECT_NAME]\n" 1087 " %1$s %2$s help\n" 1088 "\n" 1089 " " HELP_SPEC_OPTIONS " |\n" 1090 " {-L|--use-loader} }\n" 1091 "", 1092 bin_name, "gen"); 1093 1094 return 0; 1095 } 1096 1097 static const struct cmd cmds[] = { 1098 { "object", do_object }, 1099 { "skeleton", do_skeleton }, 1100 { "help", do_help }, 1101 { 0 } 1102 }; 1103 1104 int do_gen(int argc, char **argv) 1105 { 1106 return cmd_select(cmds, argc, argv, do_help); 1107 } 1108